Neurological stimulators have been developed to treat pain, movement disorders, functional disorders, spasticity, cancer, cardiac disorders, and various other medical conditions. Implantable neurological stimulation systems generally have an implantable pulse generator and one or more leads that deliver electrical pulses to neurological tissue via electrodes. For example, neurological stimulation systems for spinal cord stimulation (SCS) may include cylindrical leads that include a lead body with a circular cross-sectional shape and one or more conductive rings spaced apart from each other at the distal end of the lead body. The conductive rings operate as individual electrodes and, in many cases, the SCS leads are implanted percutaneously through a large needle inserted into the epidural space, with or without the assistance of a stylet.
Once implanted, the pulse generator applies electrical pulses to the neurological tissue via the electrodes, which in turn modifies the function of the patient's nervous system. Conventional SCS pain treatments, for example, apply low-frequency (e.g., less than 1,500 Hz), large pulse width (e.g., greater than 50 microsecond) electrical (e.g., less than 1,500 Hz), large pulse width (e.g., greater than 50 microsecond) electrical pulses to the spinal cord to generate sensations of tingling or paresthesia that mask or otherwise alter the patient's sensation of pain. In some cases, patients report that the generated sensations of tingling or paresthesia are perceived as more pleasant and/or less uncomfortable than the underlying pain sensation. Studies have suggested (at least anecdotally) that longer pulse width electrical pulses (e.g., in excess of 450 microseconds) achieve better pain-paresthesia overlap and comfort for patients (Lee et al., Predicted effects of pulse width programming in spinal cord stimulation: a mathematical modeling study, Med Biol Eng Comput (2011) 49:765-774).